tpm2_getpubek: fix tool exit code
tpm2_getpubek: fix tool exit code

The tpm2_getpubek execute_tool() is wrongly returning a false value on
error, while the main program takes 0 to be a success value. But also
the function is expected to return an int a not a bool value, so fix
both issues.

Signed-off-by: Javier Martinez Canillas <8fdf2abf85d34ea8f3f979ef25dc1f25d94aca29@redhat.com>

01org/tpm2.0-tools,01org/tpm2.0-tools,martinezjavier/tpm2-tools,martinezjavier/tpm2-tools,martinezjavier/tpm2-tools,martinezjavier/tpm2-tools,01org/tpm2.0-tools